Perspectives on atmospheric evolution from noble gas and nitrogen isotopes on Earth, Mars & Venus. (arXiv:2003.11431v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Avice_G/0/1/0/all/0/1">Guillaume Avice</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marty_B/0/1/0/all/0/1">Bernard Marty</a>
The composition of an atmosphere has integrated the geological history of the
entire planetary body. However, the long-term evolutions of the atmospheres of
the terrestrial planets are not well documented. For Earth, there were until
recently only few direct records of atmosphere’s composition in the distant
past, and insights came mainly from geochemical or physical proxies and/or from
atmospheric models pushed back in time. Here we review innovative approaches on
new terrestrial samples that led to the determination of the elemental and
isotopic compositions of key geochemical tracers, namely noble gases and
nitrogen. Such approaches allowed one to investigate the atmosphere’s evolution
through geological period of time, and to set stringent constraints on the past
atmospheric pressure and on the salinity of the Archean oceans. For Mars, we
review the current state of knowledge obtained from analyses of Martian
meteorites, and from the direct measurements of the composition of the
present-day atmosphere by rovers and spacecrafts. Based on these measurements,
we explore divergent models of the Martian and Terrestrial atmospheric
evolutions. For Venus, only little is known, evidencing the critical need for
dedicated missions.
The composition of an atmosphere has integrated the geological history of the
entire planetary body. However, the long-term evolutions of the atmospheres of
the terrestrial planets are not well documented. For Earth, there were until
recently only few direct records of atmosphere’s composition in the distant
past, and insights came mainly from geochemical or physical proxies and/or from
atmospheric models pushed back in time. Here we review innovative approaches on
new terrestrial samples that led to the determination of the elemental and
isotopic compositions of key geochemical tracers, namely noble gases and
nitrogen. Such approaches allowed one to investigate the atmosphere’s evolution
through geological period of time, and to set stringent constraints on the past
atmospheric pressure and on the salinity of the Archean oceans. For Mars, we
review the current state of knowledge obtained from analyses of Martian
meteorites, and from the direct measurements of the composition of the
present-day atmosphere by rovers and spacecrafts. Based on these measurements,
we explore divergent models of the Martian and Terrestrial atmospheric
evolutions. For Venus, only little is known, evidencing the critical need for
dedicated missions.
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